-Laurie Metcalf is returning as Sheldon's mother in what will probably be the third episode of the season.

-Katee Sackhoff and George Takei are to appear as themselves in the episode tentatively scheduled for October 14, according to TV Squad. While Howard considers getting back together with Bernadette, the pair will present opposing points of the view on the matter as figments of Howard's imagination. Melissa Rauch appears again as Bernadette in the episode.

-Wil Wheaton is poised to make another appearance in the show, according to the Ausiello Files. Bill Prady told Michael Ausiello that he wants to revive the bitter feud between Sheldon & Evil Wil Wheaton this season.